Participation of autophagy in D-galactosamine-induced acute rat liver injury.

Autophagy is an intracellular degradation system that generates autophagosomes. Autophagy was investigated in rat hepatic lesions induced by a single intraperitoneal injection of D-galactosamine (D-GalN) that can induce hepatic lesions mimicking human viral hepatitis. Lesions consisting of hepatocyte necrosis were sporadically seen within hepatic lobules on post-injection days 1 and 2, and recovered on days 3 and 5. The number of LC3B-immunopositive cytoplasmic granules (autophagosomes) increased significantly in hepatocytes on days 1 and 2 with increased Toll-like Receptor-2 (TLR-2) mRNA. Interestingly, there were some abnormal autophagosomes with vacuolated or irregular structures, being related to decreased mRNA level of Lamp2 at 8 hr and on days 2-5. These results indicated that autophagy may participate in the development of D-GalN-induced rat acute liver lesions through its activation or degradation.